Androgen oxidation

The alkynyl steroid (96) inactivates aromatase, an enzyme which catalyzes the conversion of androgen to estrogen. It has been suggested (81JA3221) that the inactivation process involves the oxidation of (96) to an oxirene which rearranges to an oxocarbene which then binds to the enzyme prosthetic group, thus inactivating it. 

The orally effective androgen 17a-methyltestosterone (51) is prepared from 3jS-hydroxyandrost-5-en-17-one (49) by treatment with methylmagnesium iodide to give the 17a-methyl compound (50) which is then oxidized to yield... 

The major androgen or androgen precursor produced by the adrenal cortex is dehydroepiandrosterone (DHEA). Most 17-hydroxypregnenolone follows the glucocorticoid pathway, but a small fraction is subjected to oxidative fission and removal of the two-carbon side chain through the action of 17,20-lyase. The lyase activity is actually part of the same enzyme (P450cl7) that catalyzes 17tt-hydroxylation. This is therefore a dual function protein. The lyase activity is important in both the adrenals and... 

An exactly analogous enzymic transformation is encountered during the formation of oestrogen and androgen sex hormones, e.g. estradiol and testosterone respectively, where dehydroepiandrosterone is oxidized to androstenedione. 

Patients with 11/1-hydroxylase deficiency present with features of androgen excess, including masculinization of female newborns and precocious puberty in male children. There are two human isozymes that are responsible for cortisol and aldosterone synthesis, respectively. The CYP11B1 enzyme (p45011B) converts DOC to corticosterone (B) and 11-deoxycortisol (S or 11-dihydrocortisol) to cortisol (F). It is also capable of 18-hydroxylating DOC but cannot convert to aldosterone. The latter transformation is carried out by CYP11B2 (also known as aldosterone synthase), which encompasses activity for 18-hydroxylation and subsequent 18-oxidation. When CAH is associated with hypertension, deficient lljS-hydroxylase (CYP11B1) is suspected at this time more than ten mutations have been defined in affected individuals [103]. 

Boldenone (17 -boldenone) is an androgenic steroid with known anabolic properties. As the oxidation of 17-ol to 17-one steroids is a recurring pathway both in vivo and in vitro, boldenone studies in cattle liver microsomes performed in vitro showed that the most prominent metabolite formed was androst-l,4-diene-3,17-dione 111). Not long ago, it was assumed drat the presence of boldenone or its main metabolite in the urine implied illegal administration of this steroid to the animal. Evidence has been recently presented that the presence of only the boldenone metabolite in urine cannot be taken as a proof of the illegal use of tills compound because boldenone is a naturally occurring steroid in urine of cattle (12). Nevertheless, the presence of 17 -boldenone in urine at levels above... 

Kato R, Onoda K. Studies on the regulation of the activity of drug oxidation in rat liver microsomes by androgen and estrogen. Biochem Pharmacol 1970 19 1649-1660. 

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